A New Nematode of the Genus Pseudophysaloptera 
from an Okinawan Shrew 
David R. Lincicome and Bayard H. McConnaughey 1 
INTRODUCTION 
Two SHREWS, identified as Suncus murinus 
riukiuanus (Kuroda), collected on Okinawa 
Shima, Ryukyu Islands, were examined for 
parasites in August, 1945. A large number of 
nematodes were taken from the stomach, peri¬ 
toneal cavity, connective tissue in axillae of the 
hind legs, and the pericardial cavity. Two 
species are probably represented, one of which 
forms the basis of this report. It was taken 
from the stomach of each of the two hosts. 
The writers are indebted to Dr. Frank N. 
Young 2 for collection and identification of the 
shrews. 
Specimens were studied largely as wet whole 
mounts in glycerine or lactophenol. The pat¬ 
tern of the caudal papillae in the male was 
determined by dissection of more than a dozen 
specimens. The terminal portion of the body 
was severed just anterior to the bursa and re¬ 
moved to a glass slide in lactophenol. After 
removal of the membranous bursa the tail 
was flattened with ventral side uppermost and 
held in place by a cover glass. The papillae 
were then examined under the microscope. 
The worms are apparently members of the 
genus Pseudophysaloptera Baylis 1934 (family 
Physalopteridae Leiper, 1908, subfamily Phy- 
salopterinae Railliet, 1893) and have been here¬ 
tofore unrecognized in the literature. The name 
Pseudophysaloptera riukiuana is therefore pro¬ 
posed. 
1 Department of Medical Microbiology, University 
of Wisconsin, Madison, Wisconsin, and Department 
of Zoology, University of California, Berkeley, Cali¬ 
fornia, respectively. Manuscript received March 22, 
1948. 
2 Assistant professor of zoology, University of 
Florida. 
DESCRIPTION OF SPECIES 
Pseudophysaloptera riukiuana n. sp. 
General: Body white or opaque; cuticula in¬ 
flated at anterior end to form a collar in both 
sexes (see Fig. 1, d)\ two large labia each 
bearing two prominent submedian papillae and 
median amphid (see Fig. 1, d); three bluntly 
rounded teeth on the internal surface of each 
lip, these teeth appearing to originate from a 
common base in oblique en face views. The 
cuticular surface reflected over the lips appears 
denticulated as it becomes minutely folded. 
Esophagus very long and composed of two 
parts: anterior portion short, muscular; pos¬ 
terior long, glandular. Cervical papillae not 
observed. Nerve ring located at level of caudal 
half of the anterior part of esophagus. 
Female: Body length, 14.5-28.0 mm.; body 
width, 0.65-1.2 mm. Collar width, 0.27-0.44 
mm. Distance to nerve ring, 0.32-0.97 mm. 
Distance to excretory pore, 0.7-1.8. mm. Eso¬ 
phagus: total length, 3.38-5.0 mm.; length and 
width of anterior part, 0.47-0.88 X 0.13-0.22 
mm.; width of posterior part, 0.2-0.43 mm. 
Prominent, saddle-shaped constriction of body 
marking site of vulvar opening, located in the 
anterior half, third, or fourth of body. Uterus 
didelphic in type (see Fig. 1, c). Eggs 46-52 n 
in length and 26-28 /;, in width, with thick 
hyaline shells and embryonated in utero. 
Male: Body length, 9.5-14.0 mm.; body width, 
0.43-0.7 mm. Collar width, 0.22-0.38 mm. 
Distance to nerve ring, 0.32-0.42 mm. Distance 
to excretory pore, 0.47-0.65 mm. Esophagus: 
total length, 2.49-3.91 mm.; length and width 
of anterior part, 0.41-0.61 X 0.09-0.18 mm.; 
width of posterior part, 0.14-0.50 mm. Caudal 
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